Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Electrical & Electronics Expert

1) a) A 350KW, 220V, 4 pole, lap wound dc generator has the 600 armature conductors. If brushes are given a lead of 8 electrical degrees, find the number of demagnetizing and cross magnetizing ampere turns per pole. Shunt field current may be neglected.

b) describe what is commutation? Describe the various methods for improving the commutation.

2)  A short shunt compound generator supplies the current of 150A at the voltage of 230V.The resistance of shunt field is 30?, and the series field is 0.01 ?, armature is 0.02 ?, the total brush drop is 2V and the iron and friction loss is amount to 1.3KW. Determine

a) Generated E.M.F

b) Copper loss

c) Output power of the prime mover driving the generator

d) Generator efficiency.

3) The Hopkinson’s test on two shunt machines gave the following results.
Line voltage = 230V, line current excluding the field current = 25A; motor armature current = 250A; field current = 2A, Determine the efficiency of each machine under this load condition. Provided the armature resistance of each machine is 0.2 Ω.

4) a) Describe the Ward Leonard type of speed control with the help of  suitable diagram.

b) A dc shunt generator delivers a 25KW at 220V while running at 1200 rpm. Rf = 120 Ω, Ra = 0.2 Ω. Find the speed of the machine running as a dc shunt motor taking 25KW at 220V. Enable 1V per brush contact drop.

5) a) Describe the approximate equivalent circuit of the transformer

b) Draw the phasor diagram for the transformer loaded with:

i) Inductive load

ii) Resistive load.

6) Determine the all day efficiency of the 1000KVA transformer whose copper loss and iron losses at full load are 3.5KW and 5.2KW respectively. During the day of 24hrs it is loaded as follows.

Number of hrs                  Load in KW                       Power factor

4                                         1000                                   0.9

8                                          700                                    0.7

8                                         400                                     0.5

4                                          ---                                         ---


7) Deduce the equation for saving of the Cu for an autotransformer. Specify its different limitations and applications.

8) a) Describe the 3 phase to 2 phase and the 3 phase to 6 phase transformer conversion.

b) Describe the Scott connection in a transformer in detail.

9) describe what is a synchro? Describe the operation of a synchro as an error detector in detail.

10) Deduce the torque equation of the PMBL DC motor describing all the parameters included in it.

Electrical & Electronics, Engineering

  • Category:- Electrical & Electronics
  • Reference No.:- M913031

Have any Question? 


Related Questions in Electrical & Electronics

A clean 15--efficient module stc 1 m2 in size has its own

A clean, 15-%-efficient module (STC), 1 m 2 in size, has its own 90% effi- cient inverter. Its NOCT is 44° C and its rated power degrades by 0.5%/° C above the 25° C STC. a. What would its STC rated power be? b. Find the ...

1 in kademlia assume m 4 and active nodes are n4 n7 and

1. In Kademlia, assume m = 4 and active nodes are N4, N7, and N12. Where is the key k3 stored in this system? 2. In Chord, assume the size of the identifier space is 16. The active nodes are N3, N6, N8, and N12. Show the ...

A 9 kva 208 v l-l 3-phase y connected stator synchronous

A 9 kVA, 208 V (L-L), 3-phase Y connected stator, synchronous generator has a stator resistance of 0.1 ohm per phase, and a synchronous resistance of 5.6 ohm per phase. The generator is driven by a diesel engine, and is ...

1 what is the significance of a b times c 02 is it

1. What is the significance of A · B × C = 0? 2. Is it necessary for the reference vectors a 1 , a 2 , and a 3 to be an orthogonal set? 3. State whether a 1 , a 2 , anda3 directed westward, northward, and downward, respe ...

A rectangular plastic specimen of size 100 x 100 x 10

A rectangular plastic specimen of size 100 X 100 X 10 mm 3  is placed in a rectangular metal cavity. The dimensions of the cavity are 101 X 101 X 9 mm 3 . The plastic is compressed by a rigid punch until it is completely ...

Using the frequency sampling method design a linear phase

Using the frequency sampling method, design a linear phase bandstop FIR filter with cutoff frequencies Ω c1 = π/3, Ω c2 = π/2, and L h = 13. Realize the design as a frequency sampling filter.

Consider the simple rc circuit shown in fig p23-3 let r 1

Consider the simple RC circuit shown in Fig. P2.3-3. Let R = 1 kΩ and C = 1 nF. (a) Find the system transfer function. (b) Plot the magnitude and phase responses. (c) Show that a lowpass signal x(t) with bandwidth W « 10 ...

1 what is the direction of the magnetic field for a uniform

1. What is the direction of the magnetic field for a uniform plane wave having its electric field in the positive z-direction and propagating in the positive x-direction? 2. What is intrinsic impedance? What is its value ...

A line assumed to be infinitely long and of unknown

A line assumed to be infinitely long and of unknown characteristic impedance is connected to a line of characteristic impedance on which standing wave measurements are made. It is found that the standing wave ratio is 3 ...

Power mosfet breakdown voltage 800v must conduct 10a when

power mosfet breakdown voltage 800v must conduct 10A when on with a maximum on state voltage 4v.If the current density in the mosfet must be limited to 200A/cm,estimate the conduxting area

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

WalMart Identification of theory and critical discussion

Drawing on the prescribed text and/or relevant academic literature, produce a paper which discusses the nature of group

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro